#include<cstdio>

 #include<algorithm>

 #include<set>

 #include<vector>

 #include<cstring>

 #include<iostream>

 using namespace std;

 #define X first

 #define Y second

 const int maxn=+;

 pair<int,int>a[maxn*];

 vector<int>v;

 struct Node{

     int l,r;

     int col;

     int lazy;

     void update(int x){

         col=x;

         lazy=x;

     }

 }tree[maxn*];

 bool vis[maxn*];

 /*void push_up(int x){

     if(tree[x<<1].col!=tree[x<<1|1].col||tree[x<<1].col==-1||tree[x<<1|1].col==-1)tree[x].col=-1;

 }*/

 void build(int x,int l,int r){

     tree[x].l=l,tree[x].r=r;

     tree[x].col=-;

     if(l==r){

         return ;

     }

     else {

         int mid=l+r>>;

         build(x<<,l,mid);

         build(x<<|,mid+,r);

     }

 }

 void push_down(int x){

     if(tree[x].col==-)return;

     tree[x<<].col=tree[x<<|].col=tree[x].col;

     tree[x].col=-;

 }

 void update(int x,int l,int r,int val){

     int L=tree[x].l,R=tree[x].r;

     if(l<=L&&R<=r){

         tree[x].col=val;

         return ;

     }

     else {

         push_down(x);

         int mid=(L+R)>>;

         if(l<=mid)update(x<<,l,r,val);

         if(mid<r)update(x<<|,l,r,val);

     //    pudh_up(x);单点查询不需要合并

     }

 }

 long long query(int x,int a){

     int L=tree[x].l,R=tree[x].r;

     if(L==R)return tree[x].col;

     push_down(x);

     int mid=L+R>>;

     if(mid>=a)query(x<<,a);

     else if(mid<a)query(x<<|,a);

 }

 int main(){

     int t;

     scanf("%d",&t);

     while(t--){

         int n;

         memset(vis,,sizeof(vis));

         scanf("%d",&n);

         for(int i=;i<n;i++){

             scanf("%d%d",&a[i].X,&a[i].Y);

             v.push_back(a[i].X);

             v.push_back(a[i].Y);

             v.push_back(a[i].Y+);

         }

     sort(v.begin(),v.end());

     int num=unique(v.begin(),v.end())-v.begin();

     for(int i=;i<n;i++){

       a[i].X = lower_bound(v.begin(), v.begin() + num, a[i].X) - v.begin() + ;

       a[i].Y = lower_bound(v.begin(), v.begin() + num, a[i].Y) - v.begin() + ;

     }

     build(,,num);

     for(int i=;i<n;i++){

         update(,a[i].X,a[i].Y,i+);

     }

     int ans=;

     for(int i=;i<=num;i++){

         int col=query(,i);

     //    cout<<col<<endl;

         if(col!=-&&vis[col]==){

             vis[col]=;

             ans++;

         }

     }

     printf("%d\n",ans);

     }

     return ;

 }